As a member used under a plasma irradiation environment such as a semiconductor manufacturing apparatus, a member having a highly plasma resistant coat formed on the surface of the member is used. The coat is based on, for example, an oxide such as alumina (Al2O3), yttria (Y2O3) or the like, or a nitride such as aluminum nitride (AlN) or the like.
On the other hand, in an oxide-based ceramics, a volume of a film expands and a crack or the like occurs with fluoridation due to a reaction with a CF-based gas, and as a result, particles are generated, therefore use of fluoride-based ceramics such as originally fluoridated yttrium fluoride (YF3) or the like is proposed (JP 2013-140950 A (Kokai)). A thermal sprayed material made of granules including oxyfluoride of yttrium and YF3 and a plasma resistant coating based on YF3 are proposed (JP 2014-009361 A (Kokai), JP 2016-076711 A (Kokai)).
Since YF3 is decomposed, for example, at a high temperature of approximately 1000° C. to 1100° C., a sintering temperature when manufacturing a sintered body of YF3 is supposed to be up to, for example, approximately 800° C. (JP 2003-146755 A (Kokai)) However, when the sintering temperature is low, it is difficult to increase a density sufficiently. Fluorine gas generated in the sintering is toxic, and has a safety problem as well. Then, the structure of YF3 is manufactured by a method of a thermal spray or the like. However, it is difficult to manufacture the structure including YF3 with a sufficient density by the thermal spray, and there is a problem of being inferior in the plasma resistance.
It is also considered that rare-earth oxyfluoride is used, with expectation of having resistance to both of CF-based plasma and Cl-based plasma.
For example, it is considered that a sintered body including oxyfluoride of yttrium is sintered under inactive atmosphere such as vacuum or nitrogen atmosphere (Japanese Patent No. 4160224, Japanese Patent No. 5911036). This method can suppress mixing of yttria (Y2O3) into the obtained sintered body by sintering under the inactive atmosphere. However, in the sintered body, there is a problem that a crystal forming particle becomes large due to grain growth accompanying sintering and thus the particle tends to be large.
For example, it is also considered that a thermal spray film is formed by using oxyfluoride of a rare-earth element as a source material (Japanese Patent No. 5927656). However, in the thermal spray, oxide is produced by oxygen in the atmosphere upon heating. Therefore, Y2O3 may be mixed in the obtained thermal spray film and control of compositions may be difficult. The thermal spray film has yet a problem in denseness.
On the other hand, JP 2016-027624 A (Kokai) discloses that it is possible to form the highly plasma resistant structure of Y2O3 at a normal temperature by an aerosol deposition method. It is possible to manufacture a film at the normal temperature by formation method of the structure based on mechanical shock such as the aerosol deposition method or the like. For this reason, it is possible to fabricate safely the structure including a compound including yttrium and fluorine by the aerosol deposition method without fear of thermal decomposition and influence of toxic fluorine gas.